Bell-buzzer construction



June 29, 1954 Filed April 3, 1950 A. C. GROHSGAL BELL-BUZZERCONSTRUCTION 2 Sheets-Sheet 1 ,fl.0.6{r0kayal INVENTOR I BY I] 1 Y I IATTORNEYS.

A. C. GROHSGAL BELL-BUZZER CONSTRUCTION June 29, 1954 '2 Sheets-Sheet 2Filed April 3, 1950 13.65 Grahajy'al INVENTOR ATTORNEYS.

Patented June 29, 1954 UNITED STATES ar OFFICE BELL-BUZZER CONSTRUCTIONApplication April3, 1950, Serial No. 153,66'7

1 Claim.

This invention relates to a construction for an electric signallingbell, buzzer, or bell-buzzer combination adapted for use inthe home,office, shop, or other locations.

In many structures, such as older homes, electric bells or buzzers aregenerally mounted on the surface of a room wall with such fasteningmeans as wood screws, with the wiring leading to the device beingfrequently exposed. However, in newer structures such asthe newer typeofiice buildings and residences, bell wiring is concealed in conduittubing extending to outlet boxes recessed in the interior walls orpartitions of the structure, the bell or buzzer being mounted upon saidboxes with machine screws.

These completely different conditions of mounting have, heretofore, tomy knowledge required different types of bases or back plates for thebells or buzzers, and the commercial field heretofore has had noelectric signalling devices adapted for universal mounting, so that asignal device is designed for either surface mounting or switch boxmounting as necessary by reason of the particular mounting conditions.

One important object of the present invention is to provide an electricsignalling device wherein said device will be designed in such a manneras to be capable of being mounted either upon the surface of a wall orupon an outlet box, this universally mountable device being highlydesirable for the purpose of reducing manufacturing costs. In thisparticular art, where devices of the type stated are manufactured inconsiderable quantities and under conditions which dictate the necessityof reducing costs to an absolute minimum,

a saving in manufacturing costs is of great importance even thoughseemingly infinitesimal.

Another important object is to provide an electric signalling devicewherein, in a bell construction, the housing or cover therefor and thetonal element are resonated to each other so as to create a mellowsignal in contrast to the harsh sound of door bells as commonlyconstructed.

Still another important object is to provide a back plate constructionfor electric signalling devices of the type stated that will be adaptedfor the mounting of a bell only, bell and buzzer combination in side byside relationship, or buzzer only at a central location on said backplate.

witli the foregoing and other objects in View which will appear as thedescription proceeds, the invention consists of certain novel details ofconstruction and combinations of parts, hereinafter more fully describedand pointed out in the claim, it being understood that changes may bemade in the construction and arrangement of parts without departing fromthe spirit of the invention as claimed;

Referring to the drawings- Fig. l is a side elevational view of the backplate and. outlet box on which said plate is mounted, an electric bellmechanismbeing shown in side elevation and the cover being shown inlongitudinal section;

Fig. 2 is a section taken substantially on line 22 of Fig. 1.

Fig. 3 is a section substantially on line 3--3 of Fig. 1 on a somewhatreduced scale.

Fig. 4' is a. perspective view of the back plate.

Fig. 5 is an enlarged fragmentary perspective View of the cover showingthe means for attachment of. the cover to'the-backplate.

Referring to the drawings in detail, the mounting base is of steelconstruction, preferably, and comprises an elongated rectangular plate 2carrying at its perimeter a substantially perpendicular reinfcrcing andspacing. flange 2". Aperipheral contact flange I is carried by thespacing flange 2' and extends outwardly therefrom at the edge thereofremote from the plate 2. Intermediate the ends of the plate, a pair ofupstanding gripping lugs 3 of flared formation (see Fig. 1) are formedupon the opposite longitudinal edges of said contact flange I-.

Entering one end of the plate 2 is a flanged recess 5 the fiange ofwhich merges into the flange I. A keyhole slot 4; is. provided in theperipheral flange I, within the confines of the recess 5. Adjacent theother end of the plate 2 is a perforated dimple 6, the bottom of whichlies in the plane of thehange I. The slots and opening 5 are forreceiving fastening means for attaching the mounting base either to awall surface or outlet box as desired.

Formed in the plate 2 at diiferent corners.

thereof said body are the openings 1, 3, and s respectively for thepassage of a common lead, bell lead, and buzzer lead respectively,extending from a source of electricity to the terminals providedtherefor upon the signal mechanisms.

In the center of the plate 2 I provide the open ing Ill flanked by apair of smaller openings II, the, opening, It being adapted forreceiving a bobbin core when the back plate is to support a buzzer only,center openings II receiving small pins extending from a bobbin mountedabove the opening Ill for preventing rotation of said bobbin.

Adjacent one end of the plate 2, there are formed thereinthe'core-re'ceiving opening I2 and anchor pin openings I3 for mountingof the bell 3 bobbin or coil, there being formed in the plate 2 adjacentsaid openings 52 and I3 the opening M flanked by the anchor pinreceiving openings l5 for mounting of the coil of a buzzer when theplate 2 is to support a bell-buzzer combination.

In the present instance there is illustrated a bell buzzer combination,but it will be understood that this is shown purely for the sake ofexample, the plate being equally well adapted, as apparent from theabove description and from Fig. 4 of the drawings, for mounting of abell only (opening [4), or buzzer only (opening Ill).

For supporting the tonal element of the bell, the plate 2 is formed withthe outstruck upstanding bracket [6 of inverted U shape, formed with theopenings I I for receiving fastening elements.

Considering now the construction of the actuating mechanisms for thebell and buzzer of the illustrated example, it will be appreciated thatthese are identical in all respects with the exception of the armatureformation thereof. Accordingly, angular brackets l8 are positioned overthe openings l2 and M respectively, these angular brackets having attheir upper ends the outwardly and upwardly extended extensions 1 9 forattachment of the armatures and contact springs.

Supported upon the lower end of the brackets l 8 are the bobbins orcoils 20, the cores of which project through the openings l2 and I4 andare peened over the edges of said openings for fixed mounting of thecoils and brackets upon the plate 2.

Secured to the upper ends of the coils 2B are the fiber plates 2| thesebeing extended laterally beyond the coils at one side for mounting onthe laterally projecting portions of said plates of conductive terminals22 having the inturned end wings 23 gripping the fiber plates 2|. Theterminals 22 are formed with the central threaded openings receiving theterminal screws 24.

Secured to the front portions of the respective plates 2| and havingtheir upper ends spaced above said plates are the contact brackets 25.These brackets at their free ends overlie the free ends of contactsprings 26 fixedly secured at their other ends to the extensions [9 ofthe supporting brackets i8. Rigidly secured to the contact springs 26adjacent the last-named ends of said springs are the armatures 27, 28 ofthe buzzer and bell respectively.

The armature 2? of the buzzer terminates below the bracket 25 of thebuzzer, but the armature 28 of the bell is integrally formed with theelongated horizontally extending striker 29 having the boss 38 formed inits bottom surface for striking the folded tonal element 31 which isU-shaped in cross section. Fastening means 32 fixedly sesure said tonalelement to the supporting bracket i B in a position in which it iselevated above the plate 2 as best seen from Figs. 1 and 3.

In the illustrated example, the bell-buzzer combination is mounted upona conventional outlet box 33 having the usual knock-outs 34, this outletbox being of the type that is mounted in recessed position within a roomwall as is common in newer structures.

A buzzer lead 35 extends through the opening 9 from the outlet box 33and is secured by the terminal screw 24 to the buzzer terminal. A belllead 36 extends through the opening 8 and is secured by the terminalscrew 24 to the bell terminal. A common lead 31 extends through opening'1 from the outlet box and is attached by terminal screw 38 to the plate2, the said plate being formed with an apertured boss 39 in one corner,

4 into which said screw 38 is threaded. The boss 39 is provided so as topermit the terminal screw 38 to be turned home to its full extentwithout coming into engagement with the surface of a wall or the like onwhich said mounting base is mounted in a surface-mounting arrangement.

As a means for mounting the mounting base upon a conventional outlet box33, I provide the machine screws 40, 4! extending through the opening 6and keyhole slot 4 respectively, the outlet box 33 having the inturnedend wings 42 formed with threaded screw-receiving openings in which themachine screws 40, 4| threadedly engage for rigid attachment of themounting base to said outlet box.

If the mounting base were to be mounted in a surface mountingarrangement, the user would simply substitute wood screws for themachine screws 40, H, and position the flange I of the mounting basedirectly against the surface of the room wall, threading the wood screwsinto the room wall for rigid mounting of the mounting base directlythereupon.

It may be noted, in this connection, that the mounting base is so formedas to be adapted for either surface mounting or outlet box mounting, asnecessary or desired. In either instance an efficiently mounted mountingbase results, the back plate having no projections on its undersidewhich would prevent its being readily mounted upon a wall surface, andbeing at the same time mountable upon any conventional outlet box.

Considering now the cover portion of the electric signalling device,this is formed of plastic material preferably, and in general comprisesa box-like cover 43 covering the mounting base and signalling mechanismsupported thereupon completely.

The bottom or plate-engaging edge of the cover 43 is molded with aperipheral rib 44, open at opposite sides of the cover as readily seen Ifrom Fig. 5, to provide flared spaces 45 in which engage the grippinglugs 3 of the mounting base. Mounting of the cover 43 upon the mountingbase is achieved simply by pressing the opposite side walls of the coverinwardly, these having a certain amount of resiliency by reason of theinherent characteristics of the material of which they are made, afterwhich the cover is positioned upon the peripheral flange 1 and released,the flared wings 3 now engaging in the spaces or recesses 45 providedtherefor to mount the cover upon the mounting base in its properposition. The cover is otherwise wholly free of connections to themounting base.

Formed in the top portion of the cover 43, above the tonal element 3|,is the opening 46 for passage of the sound waves, this opening beingcrossed by a plurality of parallel ribs 41 providing a protective grillwork. Integrally formed upon the cover 23 and depending from the edgeportion of the opening 46 is the skirt 48 disposed above and shaped tothe general outer configuration of the tonal element 3 l as readily seenfrom Figs. 1 and 2, said skirt 48 terminating a short distance abovesaid element and having the clearance notch or recess opening 49 throughwhich extends the striker 29 of the bell mechanism.

It is an important characteristic of the invention that the particularformation and arrangement of the cover or housing 43 relative to thetonal element 3| resonates the cover to the tonal element to produce amellower tone than that commonly produced by electric signalling bells.

The resonating of the cover 43, to the tonal element 3! is accomplishedby relating the thickness of the cover to the vibrations of the tonalelement in a manner to cause the period of vibration of said cover to beattuned closely to ,that of the tonal element. This resonatingcharacteristic of the cover is enhanced by providing the skirt 48 andthus defining an interior cubic resonance chamber immediately adjacentthe tonal element 3! which is absorbed by certain sound waves emanatingfrom the tonal element.

What is claimed is:

In an electrical signalling device a mounting base, a bracket carried bythe base and extending perpendicularly therefrom adjacent one sidemounted on said mounting base andenclosing the signaling means, a skirtcarried by the cover and extending toward the base for defining aresonance chamber adjacent said tonal element, said skirt having arecess opening therethrough to accommodate the striking means, and saidcover having an opening extending therethrough and. communicating withthe resonance chamber through which may escape sound produced by thetonal element.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,014,444 Miller Sept. 17, 1935 2,070,020 Miller Feb. 9, 19372,120,153 Rittenhouse et a1. June '7, 1938 2,126,433 Voightlander Aug.9, 1938 2,140,577 Gaynor Dec. 20, 1938 2,194,507 Lord et a1 Mar. 26,1940 2,333,515 Brewer et a1. Nov. 2, 1943 2,391,698 Grohsgal Dec. 25,1945

